Biochemistry serves as a fundamental discipline in the life sciences, exploring the chemical processes and biomolecules that underlie biological systems. It bridges the gap between biology and chemistry, investigating the molecular basis of life. Biochemistry delves into the study of macromolecules such as proteins, nucleic acids, carbohydrates, and lipids, as well as the intricate interactions and reactions that occur within cells. It encompasses vital topics such as metabolism, energy production, cellular respiration, and photosynthesis. The field examines DNA, RNA, and gene expression to unravel the genetic information and molecular mechanisms that govern living organisms. Additionally, biochemistry explores the molecular structures, chemical bonds, and synthesis of biomolecules, as well as the diverse biochemical pathways and cellular functions they regulate. It also encompasses aspects of molecular genetics, protein synthesis, enzyme kinetics, biochemical regulation, and cell signaling. Biochemistry finds applications in various areas including biotechnology, pharmaceuticals, genetic engineering, and the study of metabolic diseases. It plays a pivotal role in advancing our understanding of life at the molecular level and holds significant implications for numerous scientific and medical advancements.

1. Introduction to Biochemistry
Dr.Navaneethakrishnan PharmD.,
Assistant Professor
Department of Pharmacology

2. INTRODUCTION
 Biochemistry is the study of the chemical processes in living organisms –
both plants and animals.
 It deals with the structure and function of cellular components such as
proteins, carbohydrates, lipids, nucleic acids and other biomolecules.
 Biochemistry can be divided broadly into four branches:
1. Medical biochemistry
2. Animal biochemistry
3. Plant biochemistry
4. Biochemistry of microorganisms.

3. History of Biochemistry
 Monomers and Polymers are a structural basis in which the
four main macromolecules or biopolymers, (Carbohydrates,
lipids, proteins and nucleic acids) of biochemistry are based
on.
 Monomers are smaller micro molecules that are put together
to make macromolecules.
 Polymers are those macromolecules that are created when
monomers are synthesized together. When they are
synthesized, the two molecules undergo a process called

4. Principles of Biochemistry - Cells
 Cell is the structural and functional unit of all living organisms.
 Cells are highly organized and constant source of energy is required to
maintain the ordered state.
 Living processes contains thousands of chemical reactions. Precise regulation
and integration of these reactions are required to maintain life.
 Certain important reactions E.g. Glycolysis is found in almost all organisms.
 All organisms use the same type of molecules: CHO, proteins, lipids & nucleic
acids.
 Instructions for growth, reproduction and developments for each organism is
encoded in their DNA.

5. Cells
 Basic building blocks of life.
 Smallest living unit of an organism.
 Grow, reproduce, use energy, adapt, respond to their
environment.
 Many cells cannot be seen with the naked eye.
 A cell may be an entire organism or
it may be one of billions of cells that
make up the organism.

6. Cells may be Prokaryotic or Eukaryotic
 Prokaryotes include bacteria & lack a nucleus or membrane-
bound structures called organelles.
 Eukaryotes include most other cells & have a nucleus and
membrane-bound organelles (plants, fungi, & animals).

7. Prokaryotes Eukaryotes
Do not carry well developed
nucleus.
Eg: Bacteria, Ameoba,
Clamydomonas.
Well developed nucleus Eg: Plant
and Animal cell.
Simple celled Multicellular
Do not have sub-cellular organelles Have sub-cellular organelles
(Mitochondria, Golgi apparatus,
Ribosomes, Cytoplasma,
Endoplasmic
Reticulum, Peroxyzomes.
Cell constituents are:
1. Plasma membrane. 5. Lysozomes.
2. Mitochondria. 6. Peroxysomes.
3. Endoplasmic reticulum. 7. Nucleus.
4. Golgi apparatus. 8. Cytoplasm

8. Cell Constituents Explanation Function
Plasma
membrane
• Outer most covering of the cell.
• Made up of proteins, lipids and
carbohydrates.
• Lipids present in plasma membrane
is phospholipid. Lipids are bilayered.
• Phospholipid have head and tail
region. Head is hydrophilic polar and
tail is hydrophobic non-polar.
• Sometimes glycolipids and
cholesterol are also present in the
plasma membrane.
• It resembles like fluid mosaic model.
• Proteins two types, one is extrinsic-
outside of plasma membrane.
• Other is intrinsic- Inside of plasma
membrane.
• Transport of ions
(ca+, Na+, K+,
Biomolecules,
glucose).
• Carry receptors for
hormones and
neurotransmitters.

9. Cell
Constituents
Explanation Function
Mitochondria
• Power house of the cell.
• Double membrane structure.
• Inner membrane folded in
the form of cristae.
• Centre part is called as
matrix.
• ATP synthesis.
• Electron transport chain occurs
in inner membrane.
• Oxidative phosphorylation
occurs and it is also a Part of
urea cycle and heme synthesis.
Endoplasmic
Reticulum
• Tubular in structure.
• Two types, Rough ER and
Smooth ER.
• Due to presence of
Ribosomes Rough ER is
named so.
• RER- Protein synthesis and
secretion.
• SER- Steroid hormones,
Phospholipids has been
synthesized.
• Metabolism of various forms of
compounds takes place.

10. Cell
Constituents
Explanation Function
Golgi
apparatus
• Tubular in shape.
• Present almost in all cells in
our body (250 types of cells).
• Matured RBC do not contain
mitochondria and golgi
apparatus.
• Important role in post-
transcriptional modification.
• Sorting of proteins.
• Export of proteins.
• Vesicular organelles (mostly
round like).
• Formed from golgi
apparatus.
• Membrane of lysozomes has
more thickest membrane.
• Carry hydrolytic (Important
role in destruction) enzymes.
• Intra cellular digestion of
Macromolecules
(Carbohydrates, Lipids,
Nucleic acids, Proteins).
• Sucidal bags.
• Destruction of bacteria.
• Hydrolysis of nucleic acid,
protein, glycosamino glycans,

11. Cell Constituents Explanation Function
Peroxysomes
• Resemble like lysosomes.
• Synthesized from either
SER/ from pre-existing
peroxysomes.
• Carry peroxidase enzyme,
catalyse enzyme etc.
• These enzymes play important
role in detoxification.
• Metabolism of peroxide and
oxidation of long chain fatty
acids.
Cytoplasm /
Cytosol
• Granulated structures.
• All the sub cellular
organelles are embedded.
• Part of Gluconeogenesis.
• Site for most of the metabolic
activities like HMP pathway,
urea cycle, glycolysis and
synthesis of purins and
pyramidins.

12. Cell
Constituents
Explanation Function
Nucleus
• Nucleolus (Site for DNA
replication and
transcription), chromatin
(Thread like structure).
• Germ cells reproduce
somatic cells= mitosis and do
not reproduce. Spherical in
shape.
• Covered by nuclear
membrane.
• The remaining site of
nucleolus is filled in
• Storage of DNA, replication
and repair of DNA,
transcription and post-
transcriptional processing.
• Nucleolus present inside the
nucleus helpful in synthesis of
rRNA and formation of
ribosomes.

13. TRANSPORT PROCESS ACROSS THE CELL
MEMBRANES
Biological membranes are semi-permeable membrane (allow only
certain into the cell).
Two types of transport process-
 Passive transport-
Simple diffusion
Facilitated diffusion.
 Active transport-
Primary active transport
Secondary active transport ( co-transport and Counter
transport).

14. Transport
process
Explanation
Simple
diffusion
• Ions move from higher concentration to lower concentration.
• Lipophillic (lipid solving substances) can be transported.
Facilitated
diffusion
• Other name is uniport and carrier medicated diffusion.
• Ions itself cannot be translocated for higher concentration to
Lower concentration.
• It is transported through carrier which is located on the
membrane of cell.
• Water soluble substances can be transported by this
mechanism. Because plasma membrane is made of only
lipids and proteins.
Passive transport-
 Lipid soluble molecules can easily transport from intracellular to
extracellular.
 Ions are being transported without utilization of ATP/carrier/energy. Ions
move from higher concentration to lower concentration.

15. Transport
process
Explanation
Primary
Active
Transport
• In this energy is derived from hydrolysis of ATP.
• Ions ( Na+, K+, Cl-, Ca++, H+) are translocated but not
biomolecules due to large size.
• Sodium-potassium pump is present. Hydrolysis of ATP is
converted into ADP and inorganic phosphate by means of
ATPase enzyme activity.
• Na+ translocated to outside whereas K+ is translocated inside
by means of Na+ K+ pump. It has great physiological
significance.
• The Na+ K+ gradient developed by this pump in cells controls
Active transport-
 The molecules move against concentration gradient and external energy
sources required (ATP) is referred as active transport.
 Eg: Ions( Na+, K+, Cl-, Ca++, H+), biomolecules, amino acids are
transported.

16. Transport
process
Explanation
Secondary
Active
Transport
• It uses energy generated by electrochemical gradient.
• It is not directly coupled with hydrolysis of ATP.
Co-
Transport
• Both substances moves simultaneously across the membrane in
the same direction.
• Eg: Transport of sodium and glucose to intestinal mucosal cell
from gut.
• Co-transport is also called as Symport.
Counter
Transport
• It is also called as Antiport.
• Both substances move simultaneously in opposite direction.
• Eg: Transport of Na+ and H+ which occurs in renal proximal
convoluted tubules and exchange of Cl- and HCO3- in RBC.
Active transport-

17. ENERGY RICH COMPOUNDS
 Certain compounds are encountered in the biological system
which on hydrolysis yield energy.
 Energy rich compounds is usually applied to substances which
passes sufficient free energy to liberate at least 7 cal/mole at pH
7.
 All the high energy compounds when hydrolyzed liberate more
energy than that of ATP.
 These includes phosphoenolpyruvate, 1,3-bisphosphoglycerate,
phosphocreatine etc.
 Most of the high energy compounds contain phosphate group
(exception Acetyl Co-A). Hence they are called high energy
phosphate compounds.

18. Energy-rich compounds in cells comprise five kinds of high-energy
bonds:
1. Phosphoanhydride,
2. Acyl phosphate,
3. Enolphosphate,
4. Guanidine phosphate
5. Thioester bonds.
 Phospho anhydride bond is formed between two molecules of
phosphoric acid (H3POs). In hydro-lysis of 1 mol of this bond is
liberated approximately 30.5 kJ/mol bond.

19.  Enolphosphate bond is formed when phosphate group is
attached to the hydroxyl group which is bounded to carbon
with double bond.
 Acylphosphate bond is formed by the reaction of carboxylic
acid with phosphate group.

20.  Guanidine phosphate bond is formed if phosphate group is
attached to guanidine group.
 Thioester bond —is not typical high-energy bond because here
is not energy rich phosphate, but here is acyl rest of carboxylic
acid attached to Sulphur from -SH group.

21.  The high energy compounds posses acid anhydride bonds
(mostly phosphor anhydride bonds).
 which are formed by condensation of two acidic groups or
related compounds.
 These bonds are called high energy bonds since the free
energy is liberated when these bonds are hydrolysed. Symbol
(-) to represent high energy bond.

22. ADENOSINE TRIPHOSPHATE (ATP)
 Adenosine triphosphate (ATP) is an organic compound that
provides energy to drive many processes in living cells, such
as muscle contraction, nerve impulse propagation, condensate
dissolution, and chemical synthesis. Found in all known forms
of life, ATP is often referred to as the "molecular unit
of currency" of intracellular energy transfer.
 When consumed in metabolic processes, it converts either to
adenosine diphosphate (ADP) or to adenosine
monophosphate (AMP). Other processes regenerate ATP.
The human body recycles its own body weight equivalent in
ATP each day.

23. ADENOSINE TRIPHOSPHATE (ATP)
 Adenosine triphosphate (ATP), energy-carrying molecule found in the cells of
all living things. ATP captures chemical energy obtained from the breakdown
of food molecules and releases it to fuel other cellular processes.
 It is a high energy compound due to the presence of 2-phosphoanhydride
bonds in triphosphate unit. It serves as the energy currency of the cell.
 Hydrolysis of ATP releases large amount of energy.
ATP + H20  ADP + Pi (7.3 cal)
 Energy liberated is utilized for various process like muscle contraction, active
transport etc. It acts as donor of high energy phosphate to low energy
compounds to make them energy rich.
 ADP can accept high energy phosphate from compounds possessing higher
free energy content to form ATP. ATP-ADP cycle- fundamental basis of
energy exchange reactions in living system. They act as link between
catabolism and anabolism in biological system.

24. Cyclic AMP (cAMP) is a small molecule that acts as a secondary messenger in
many cellular signalling pathways. It is formed from ATP (adenosine
triphosphate) by the enzyme adenylate cyclase and can activate a variety of
downstream signalling pathways. cAMP is particularly important in
regulating cellular responses to hormones and neurotransmitters.
Cyclic adenosine monophosphate (cAMP) is a signalling molecule that plays
an important role in many biological processes. Here are some of its
significances:
 Second messenger: cAMP acts as a second messenger in intracellular signal
transduction pathways. It is produced in response to extracellular signals
such as hormones, neurotransmitters, and growth factors, and it then
activates downstream signalling pathways, leading to various cellular
responses.
 Regulation of gene expression: cAMP regulates gene expression by binding
to transcription factors such as CREB (cAMP response element-binding
CYCLIC AMP (cAMP)

25.  This binding promotes the transcription of specific genes, resulting in the
synthesis of proteins that are important for cellular responses.
 cAMP can bind to and activate a transcription factor called CREB (cAMP
response element-binding protein), which in turn regulates the expression
of genes involved in cell growth, differentiation, and survival.
 Metabolism: cAMP regulates metabolism by activating protein kinases that
phosphorylate and activate enzymes involved in the breakdown of
glycogen and fat. This leads to the release of energy that can be used by the
cell.
 Cardiac function: cAMP plays a critical role in the regulation of cardiac
function. It increases heart rate and contractility by activating protein kinase
A (PKA), which phosphorylates and activates ion channels and calcium
handling proteins in the heart.
 Learning and memory: cAMP is involved in learning and memory
formation. It activates the CREB protein, which leads to the synthesis of
proteins that are necessary for long-term memory formation.

26.  Hormone regulation: Many hormones, such as glucagon, adrenaline, and
ACTH, signal through cAMP to regulate various physiological processes,
including metabolism, blood pressure, and stress responses.
 Immune response: cAMP signalling plays an important role in regulating
the immune response, including the differentiation and activation of
immune cells such as T cells, B cells, and macrophages.
 Neurotransmitter release: cAMP signalling is also involved in regulating
the release of neurotransmitters, which are crucial for communication
between neurons in the brain.
 Overall, cAMP is a crucial molecule in the regulation of many biological
processes, and its dysregulation has been implicated in a variety of diseases,
including cancer, diabetes, and cardiovascular disease.
SIGNIFICANCE OF cAMP

27.  In conclusion, cAMP is a versatile signalling molecule that
plays a crucial role in many physiological processes.
 Understanding its functions and signalling pathways can
help us develop better treatments for various diseases and
conditions.

28. THANKYOU